Curiosity uncovers clues suggesting Mars was once habitable

Mars rover Curiosity

Courtesy of NASA

This set of images compares rocks seen by NASA's Opportunity rover and Curiosity rover at two different parts of Mars. On the left is " Wopmay" rock, in Endurance Crater, Meridiani Planum, as studied by the Opportunity rover. On the right are the rocks of the "Sheepbed" unit in Yellowknife Bay,...

This set of images compares rocks seen by NASA's Opportunity rover and Curiosity rover at two different parts of Mars. On the left is " Wopmay" rock, in Endurance Crater, Meridiani Planum, as studied by the Opportunity rover. On the right are the rocks of the "Sheepbed" unit in Yellowknife Bay,... (Courtesy of NASA)

NASA'sCuriosity rover has found evidence that Mars could have once held life, scientists said Tuesday.

The one-ton rover drilled into a rock last month and collected a sample that contained essential ingredients for life on Earth, including hydrogen, oxygen, nitrogen, phosphorus and carbon, according to NASA.

Scientists believe those same elements would have provided a habitable environment for life on the Red Planet billions of years ago.

"We have found a habitable environment that is so benign and supportive of life, that if you would have been on the planet, you would have been able to drink [the water]," said Caltech scientist John Grotzinger, who leads to mission's science team.

The previous Mars mission, which sent twin rovers Spirit and Opportunity to the planet, found evidence of water.

Curiosity has fulfilled its goal of finding a habitable environment on Mars early on in the mission, and the rock it has analyzed appears to have soil that is chemically neutral, said Grotzinger. "This rock, quite frankly, looks like a typical thing we'd see on Earth."

The rover is not capable of detecting life on the Red Planet, NASA says, only clues that could suggest that the planet was once habitable.

Curiosity has been exploring an area on the Red Planet called Yellowknife Bay. The rover bored into its first rock, named "John Klein" after a former JPL project manager who died in 2011, in February. It then used its on-board chemistry set to analyze powder from inside the rock, which showed the historic results.

John Grunsfeld, head of NASA's Science Mission Directorate, said scientists can now say Mars once supported a habitable environment. He congratulated the whole Curiosity team at a press conference from NASA's headquarters in Washington, D.C.

"I know it's been years of hard work to get that far," he said. "This has just been an incredible adventure."

Curiosity will complete some science activities through the end of the month, but the rover will be mostly out of commission in April, when Mars and Earth are on opposite sides of the sun and communication is difficult.

Scientists plan to complete a second drill experiment in May. Then, the rover will begin the trek to Mt. Sharp, a three-mile-high mountain that is the main science target of the two-year mission. Curiosity landed in a region on Mars called Gale Crater on Aug. 5. The Curiosity mission is managed by NASA's Jet Propulsion Laboratory in La Canada Flintridge.

"I think what we can do now, with the issue of habitability in the bag, is we can take a more systematic search for brighter carbon signal," said Grotzinger. "We're really excited to get started on this now."